#region The MIT License
// The MIT License
// 
// Copyright (c) 2009 octalforty studios
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#endregion
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;

namespace octalforty.Componento.ComponentModel.Installation
{
    public class DbManager
    {
        public static IEnumerable<T> ExecuteDataReader<T>(IDbTransaction dbTransaction,
            string selectStatement, Func<IDataReader, T> mapper)
        {
            using(IDbCommand dbCommand = dbTransaction.Connection.CreateCommand())
            {
                dbCommand.CommandText = selectStatement;

                using(IDataReader dataReader = dbCommand.ExecuteReader())
                {
                    while(dataReader.Read())
                        yield return mapper(dataReader);
                } // using
            } // using
        }

        public static void Execute(DbProviderFactory dbProviderFactory, IDbTransaction dbTransaction,
            string statement, string[] names, object[] values)
        {
            using(IDbCommand dbCommand = dbTransaction.Connection.CreateCommand())
            {
                dbCommand.CommandText = statement;

                for(int i = 0; i < names.Length; ++i)
                {
                    IDataParameter dataParameter = dbProviderFactory.CreateParameter();
                    dataParameter.ParameterName = names[i];
                    dataParameter.Value = values[i];

                    dbCommand.Parameters.Add(dataParameter);
                }

                dbCommand.ExecuteNonQuery();
            } // using
        }

        public static T ExecuteScalar<T>(DbProviderFactory dbProviderFactory, IDbTransaction dbTransaction,
            string statement, string[] names, object[] values)
        {
            using(IDbCommand dbCommand = dbTransaction.Connection.CreateCommand())
            {
                dbCommand.CommandText = statement;

                for(int i = 0; i < names.Length; ++i)
                {
                    IDataParameter dataParameter = dbProviderFactory.CreateParameter();
                    dataParameter.ParameterName = names[i];
                    dataParameter.Value = values[i];

                    dbCommand.Parameters.Add(dataParameter);
                }

                object scalar = dbCommand.ExecuteScalar();
                return (T)scalar;
            } // using
        }

        public static IEnumerable<T> ExecuteDataReader<T>(DbProviderFactory dbProviderFactory, IDbTransaction dbTransaction,
            string statement, string[] names, object[] values, Func<IDataReader, T> mapper)
        {
            using(IDbCommand dbCommand = dbTransaction.Connection.CreateCommand())
            {
                dbCommand.CommandText = statement;

                if(names != null)
                    for(int i = 0; i < names.Length; ++i)
                    {
                        IDataParameter dataParameter = dbProviderFactory.CreateParameter();
                        dataParameter.ParameterName = names[i];
                        dataParameter.Value = values[i];

                        dbCommand.Parameters.Add(dataParameter);
                    }

                using(IDataReader dataReader = dbCommand.ExecuteReader())
                {
                    while (dataReader.Read())
                        yield return mapper(dataReader);
                } // using
            } // using
        }
    }
}
